Method of making artificial stone.



m. STEHM. METHOD OF MAKING ARTIFICIM; STONE,

APPLICATON FILED MAY 4; 1906.

1,182,862. Patented May 9, 1916.

2 SHEETS -SHEET I.

Patented May 9,1916.

2 SHEETS-SHEET 2- F. R. STEHM. METHOD OF MAKING ARTIFICIAL STONE.

APPLICATION FILED IAY H. 1906.

. EDSTATES PATE T oFFi ream: ms'rnnm; or mas MOINES; Iowa; lemma, BY manor Ann MESNE ASSIGN- znnucrs ro rnn nnamm. eoucnnrrn AND MACHINERY COMPANY, or one MOINES, ,xowmn comomrrou or SOUTH DAKOTA.

whom it may concern:

Be it known thatlpFnAn-K R. .S'rr:rur, a citizenof the United States, residing at Des.

Moines, in theconnty of Polk and State of 1 {1 ,have invented a certainnew and use- :ful Method; of Making. Artificial Stone, of

'- My invention consistsin the several steps ffof theprocess andintheir arrangement and combinationwvitheach other, whereby the a i objects conteinplated are attained, as herezo inaftermore fully set forth, pointed out in a my laimand illustratedin the accompanying drawings, in'which igurel shows aperspective view of an apparhtus designed for the practice of my improved; method. Fig. 2'shows a similarv jVdGW nithfthe mold elevated above the-com-- pletedxfartificial stone. Fig. 3 shows a vertical, longitudinal, sectional view of the ishing platedetached Fig. 4 shows a,

. 3o fjierspective-view of theysame plate. Fig. 5 shows a transverse, sectional view of the j "finishing plate. lFig.fishowsa central. 1ongitu'di nal, sectional view of a mold, a finishng"? plate andfapartition in the mold, sa d *finifsliing plate havin therein a quantity of surfacingmaterial.' ig. 7 shows a similar view with the mold filled with material for forming thebody of the stone and illus- ,trating the surfacing. material forced up 401a ardlybetween th'epartitionand the ad ay a cent end of the finishing plate. Fig. 8 shows a rsimlhir. viewwith a piesser, plate introhmshing plate raised to .a'npoint above the stop! of the mold. Figs 9 shows a' similar :vifivwvith more material for forming the so boayof the stoneadded after the removal ofl the presscr platc,1.and Fig. 10 showsa f vsimilar view with the presser plate in posii 1 tion and the artificial I stone completely a formed and the partition removed.

Specification Letters Patent.

slightly curved corner-portion 23.

cedlinto the mold andithe n'iaterial for i as ning the body of rtlieartificial stone coin 's'ed and the finishing materialbetweenpartition and thewadjacent end of the i nnrnon or MAKING an'rmremt. s'troun.

Patented May 9, 1916.

a plicatio filed May 14, 1908. Serial m. 316,892.

Referring to the accompanying drawings,

the apparatus that I have illustrated forv carrying out my improved method is composed ot a trame 10 having thereon supports 11 to receive an off-bearing plate 12, which plate is formed with a raised central portion. At the top of. the frame 10 isa shaft 13 provided with crank arms 14 and links 15 connected therewith and having at their lower ends the cross pieces 16.

I Thenumeral 17 indicates a mold designe'd to rest upon the off-bearing plate and to have its ends project beyond the raised central portion thereof, so that said ends may rest upon the cross'pieres 16 and so that a ,partial revolution of the shaft 13 will elevate the mold from the off-bearing plate 12. Thefinishin'g plate is formed of thin springing metal andcomprises a base 18 having upturned side margins 19 and one upturned end margin 20, an upright end "portion 21 atriglit angles to the base 18 and side margins 22 thereon projected inwardly overrthe bottom piece 19. At the intersection of the parts 18 and 21 is a This finishing plate is of a size to enter'the mold with the outer surface of the upright end 21 flhshat "one end of the mold and the upturned marginflush at the other endof the mold and thepu'ter surfaces of the margins 19 and 22 flush with the sides of the mold. .Inorder to accomplish the best resultsand to produce a finished stone having a hard, crystallized, smooth and glossy surface, the inner faces of the finishing plateare provided with a non-erosive moistare repel-lent surface that will not adhere totthe dried and hardened stone'making, A satisfactory surface of this material. kind may be obtained by means of a routing of'japan applied thereto and baked.

. I have provided for pressing: material into the mold as follows? 2% indicates a shaft mounted in theframe l0 and provided with a crank arm 25connected to the presser plate 26 whereby a rocking movement of the said shaft will cause the presser plate I to move up and down. said preeser plate bemgdesigned to enter the mold. A -(leta 'hable partition '27 15 provided, made of thin mctaland having a cross piece 28 at its top, designed to rest upon the top of the mold avith said partition projecting transversely of the mold near the end where the end 21 of the finishing plate is located, the bottom of said partitioubeing spaced apart slightly from thegfinishing plate, substanoff-bearing plate. .tion 27 in position, as shown in Fig. (3. I' then prepare a quantity of surface forming process is shown in Fig. (3.

tially'as shown in Fig. (3, the, lower end? of said part t on norn'iallv inclined slightly toward the center of the mold.

In practising my improved llltlllMlf'I:

phtce a finishing platein a mold and then f place-tl1e ,mold and finishing plate on the I then place the partimaterial for the stone, composed of cement or its equivalent, containing a quantity of liquid so that it-will flow readily. pour this cement upon the bottom of the. finishing plate, so that it substantially fills the portion of the plate within the upturned margins of the bottom.

surfacing material upwardly between the partition and the upwardly projecting end of the finishing plate, as shown 'm'Fig. 7. I then introduce a presser plate into the mohl and force it downwardly therein to compress the material. will, when being forceddownwardly mto the mold, move the partition to a substan tially vertical 'positiomas shown in Fig. 8, and wlll sl so cause the surfacing material to, flow up to the top. of -the mold. This stage i of the process is illustrated in Fig. 8. I

then remove the presser plate and again fill up the mold with more of the same a a; terial for forming thebody of the stone.

I then remove the partition and introduce a presser plate of the size that will fit the interior of the mold and apply pressure to the material sutlicient to-fill up the opening left by the removal ofthe partition and to compress the material into a suliicie'ntly compact condition. I then elevate the mold from the off-bearing plate and from the stone and the finishing plate, the presser plate being left resting against the top of' the stone in order to permit the upward withdrawal of the mold. I then jointly remove the off-bearing plate'and the stone with its finishingplate resting upon the off-bearing plate and remove same from the machine and place them in a convenient position for drying. After the completed stone has dried for awsulficient period, varying from twoytofour days, under proper conditions, the finishing plate may be remQYBd h'om tho-stone by springingthe side 18'straight outwardly from the stone. In this way the finishingpl'ate I then This presser plateneed not bedrawn across the s'urfaca ofithe stone but is moved straight outwardly so that'the sin-face of, the stone .is not marred or scratched during this removal movement. If the. finishing'plate has been provided with a surface that is slnooth and that will not, adhere to thecement, it will be found that upon its removal, the adjacent surjacesof the stone will have crystallizedand 'tcrmed' a' surface that is a repl ca of the surface 'aga1n'st wluclr'it rested during. the

crystal-liZing process andthe finished product will have a smootluglossy surface that will not absorb moisture.

By having the finishing. plate placed directly upon the off-hearing plate, the mold may be removed by elevating it away from theofi-bearing plate without danger. of disturbing the positions of the stone and, the finishing plate, for obviously, if either the finishing plate or the stone were handled or touched before drying, there would be a great possibility of jarring the finishing plate loose and thus destroying its contact 'withthe' adjacent surface of the stone and unless this contact is complete during the entire crystallizing and drying process, the

finished 'surface'will not be assmooth an glossy as, it otherwise would.

By providing a partition adjacent to one end of the mold and spaced apart from the bottom of the mold, the surfacing material in a liquid condition may bemade t0 flow upwardly between the partition and the adjacent end of the mold, by the insertion of a quantity of thematerial for forming the body of the stone, and by applying. pressure on top of this material. It frequently hap;

pens that when the surfacing material in.

lltllid form is )laced a ainst a. finishin l =2. plate, a certain quantity of air 1s retained between the plate and stone, which air forms in bubbles and if not expelled would .mar the finished surface of the stone. I'have found that by applying pressure to the top of the stone that air bubbles may all be expelled and thesurface ofthe'sto'ne left per:

fectlysiiibotl'i. After the stone has dried adjacent. to the finishing plate for a suf ficie'nt ,period of time, the surface nearest the plate. williEpysta'llize;andthenyif the plate is removed by. springing. the sides and bottom straight outwardly from the stone, this crystallized and glpssy surface wil'l not be marred and when t finishing plate is removed, its surfacenearest the stone will be perfectly clean andh free fr rmaterial of which the stone is formed. in handling the stone before drying, the 't gglate'should spring away from the stone ano g' permit the, entrance ofair, the 'cry'stallizi-iig. process would not taker place and produce so perfectt a surface/ as though the drying and crystallization took place with the plate tightlyheld against the stone.

The terms artificial stone and concrete used in this application. are intended to apply to the same thing, and relate to a material formed of particles held together by cementitious substances.

Having thus described my invention, what I claim and desire to secure by Letters .Patent of the United States, therefore, is-

' The method of molding plastic material which consists in providing a finishing plate having an upturned end portion and an encircling rim, placing saidfinishing plate'in a mold, introducing a partition ad acent the upturned end portion, filling the bottom portion of said plate with a veneer composition thenintroducing coarser material to form the body of the molded article, and applying pressure to the top of said coarser material whereby said veneer composition will be forced upwardly between the end por- 'tions .of the finishing plate and the partition, and thereafter removing the partition and continuing the pressure whereby the veneer and body material become incorporated together.

Des Moines, Iowa, May 5, 1906. n I w FRANK R. STEHM. Witnesses:

J. RALPH ORWlG, b. F. CHRISTY." 

